Wyrd Sisters is a good one, but my only problem with Discworld is that almost ALL of them are really good ones. :) I'm glad you're going in publication order, even if there's no real wrong way to read them. :) IMHO, that is the best way, even if you bounce around the disc a bit, I think they are more logical to consume as he wrote them since he evolved things as he went along. :)

The Witches have been my favourite of the books so far. I'm also going through in release order.

I've been reading some of the Discworld books sporadically. Soul Music most recently.

I had read The Colour of Magic a while back and recall not liking it. More recently, a friend invited me to a Hogfather watching party. I enjoyed it enough that I went ahead and read the book. That prompted me to read the other related novels.

Plus, on the recommendation of said friend, Interesting Times. That one was kind of a miss for me. I don't care for Rincewind. Also, too much of the book felt like missed references to elements of a previous book.

Guards, Guards! might be the next one I pick up. Or maybe Thief of Time or Hogfather again.